Traditional casting processes for forming metal castings generally include one or more heat processing steps to impart the desired performance characteristics to the castings. These heat processing steps usually are conducted in separate furnaces or stations. A casting must be transported from one station to another in order to be processed. Generally, either the various stations are disposed in an enclosed system or are arranged in proximity to each other in an open system. Enclosed systems include fixed closed passageways between processing stations and tend to take up a significant amount of space and cannot be reconfigured easily. Open systems generally do not include fixed closed passageways between process stations. Although open systems generally allow more flexibility and take up less space than open systems, unfortunately, a casting will usually lose heat and drop in temperature during transport between stations in an open system. Since many processing steps in manufacturing a metal casting require that the casting be within a specified temperature range for heat treatment, if the casting temperature drops out of the specified range during transport, then additional heat must be supplied to the casting in the next station simply to bring the casting temperature back into the appropriate range. This remedial heating takes time that lowers the efficiency and productivity of the overall system.
Consequently, a need exists for a casting system that can provide the advantages of an open system but also reduces or eliminates any drop in the temperature of castings that are transported between processing stations.